Interest in broadband optical access networks is growing, driven by an increasing demand for high-speed multimedia services. Optical access networks are often referred to as fiber-to-the-curb (FTTC), fiber-to-the-building (FTTB), fiber-to-the-premise (FTTP), or fiber-to-the-home (FTTH). Each such network provides an access from a central office to a building, or a home, via optical fibers. As the transmission quantity of such an optical cable is much greater than the bandwidth actually required by each subscriber, a passive optical network (PON) shared between many subscribers through a splitter was developed.
For the FTTH market, for example, bidirectional data transmission requires multiple elements to be packaged and aligned in the optoelectronic module including a Diplexer for upstream and down stream data transmission or a triplexer for video overlay plus the bi-directional data transmission. However, these devices are very cost-sensitive; especially so for triplexers because triplexers require high performance including high output power, high sensitivity, and low dispersion for all three optical signals.
Traditionally, an aspheric lens is used to obtain high coupling efficiency, for example greater than 50 percent. Aspheric lenses, however, are much more expensive than ball lenses. Further, if a single ball lens is used, maximum achievable coupling efficiency is often only thirty percent, or even as low as 10%-20% coupling efficiency may be obtained. Therefore, what would be advantageous are improved triplexers including high output power, high sensitivity, and low dispersion manufactured at a relatively low cost.
The subject matter claimed herein is not limited to embodiments that solve any particular disadvantages or that operate only in particular environments such as those described herein. Rather, such environments and disadvantages are provided only to illustrate examples of technology areas in which several embodiments may be practiced.